diff --git a/BizHawk.Emulation/BizHawk.Emulation.csproj b/BizHawk.Emulation/BizHawk.Emulation.csproj
index 5b8f4d6330..61eb806bc8 100644
--- a/BizHawk.Emulation/BizHawk.Emulation.csproj
+++ b/BizHawk.Emulation/BizHawk.Emulation.csproj
@@ -442,6 +442,7 @@
     <Compile Include="QuickCollections.cs" />
     <Compile Include="Sound\CDAudio.cs" />
     <Compile Include="Sound\MMC5Audio.cs" />
+    <Compile Include="Sound\Sunsoft5BAudio.cs" />
     <Compile Include="Sound\Utilities\BlipBuffer.cs" />
     <Compile Include="Sound\Utilities\DCFilter.cs" />
     <Compile Include="Sound\Utilities\Equalizer.cs" />
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
index 2b6b403c48..f4e4557bcf 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
@@ -315,9 +315,15 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		public override byte ReadPRG(int addr)
 		{
 			bool ram;
-			addr = MapPRG(addr, out ram);
-			if (ram) return WRAM[addr];
-			else return ROM[addr];
+			byte ret;
+			int mapaddr = MapPRG(addr, out ram);
+			if (ram)
+				ret = WRAM[mapaddr];
+			else
+				ret = ROM[mapaddr];
+			if (addr < 0x4000)
+				audio.ReadROMTrigger(ret);
+			return ret;
 		}
 
 		public override void WritePRG(int addr, byte value)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
index 0ffec31197..87590b70de 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
@@ -9,6 +9,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 	class Sunsoft_5 : Sunsoft_FME7
 	{
+		Sound.Sunsoft5BAudio audio;
+
 		public override bool Configure(NES.EDetectionOrigin origin)
 		{
 			//configure
@@ -22,14 +24,33 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 
 			BaseConfigure();
+			if (NES.apu != null)
+				audio = new Sound.Sunsoft5BAudio(NES.apu.ExternalQueue);
 
 			return true;
 		}
 
 		public override void WritePRG(int addr, byte value)
 		{
-			//TODO - sound
-			base.WritePRG(addr, value);
+			int a = addr & 0xe000;
+			if (a == 0x4000)
+				audio.RegSelect(value);
+			else if (a == 0x6000)
+				audio.RegWrite(value);
+			else
+				base.WritePRG(addr, value);
+		}
+
+		public override void SyncState(Serializer ser)
+		{
+			base.SyncState(ser);
+			audio.SyncState(ser);
+		}
+
+		public override void ClockCPU()
+		{
+			audio.Clock();
+			base.ClockCPU();
 		}
 	}
 
diff --git a/BizHawk.Emulation/Sound/Sunsoft5BAudio.cs b/BizHawk.Emulation/Sound/Sunsoft5BAudio.cs
new file mode 100644
index 0000000000..2ad2a055eb
--- /dev/null
+++ b/BizHawk.Emulation/Sound/Sunsoft5BAudio.cs
@@ -0,0 +1,146 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Sound
+{
+	// YM2149F variant
+	// this implementation is quite incomplete
+	// http://wiki.nesdev.com/w/index.php/Sunsoft_5B_audio
+	public class Sunsoft5BAudio
+	{
+		class Pulse
+		{
+			Action<int> SendDiff;
+			// regs
+			int Period;
+			bool Disable;
+			int Volume;
+			// state
+			int clock;
+			int sequence;
+			int output;
+
+			public void SyncState(Serializer ser)
+			{
+				ser.Sync("Period", ref Period);
+				ser.Sync("Disable", ref Disable);
+				ser.Sync("Volume", ref Volume);
+				ser.Sync("clock", ref clock);
+				ser.Sync("sequence", ref sequence);
+				ser.Sync("output", ref output);
+			}
+
+			public Pulse(Action<int> SendDiff)
+			{
+				this.SendDiff = SendDiff;
+			}
+
+			void CalcOut()
+			{
+				int newout = 1;
+				if (!Disable)
+					newout = sequence;
+				newout *= Volume;
+				if (newout != output)
+				{
+					SendDiff(newout - output);
+					output = newout;
+				}
+			}
+
+			public void Clock()
+			{
+				clock--;
+				if (clock < 0)
+				{
+					clock = Period * 16;
+					sequence ^= 1;
+					CalcOut();
+				}
+			}
+			public void WritePeriodLow(byte val)
+			{
+				Period &= 0xf00;
+				Period |= val;
+			}
+			public void WritePeriodHigh(byte val)
+			{
+				Period &= 0x0ff;
+				Period |= val << 8 & 0xf00;
+			}
+			public void SetToneDisable(bool disable)
+			{
+				Disable = disable;
+				CalcOut();
+			}
+			public void SetVolume(byte val)
+			{
+				Volume = val & 15;
+				CalcOut();
+			}
+		}
+
+		int RegNum;
+		Pulse[] pulse = new Pulse[3];
+
+		public void RegSelect(byte val)
+		{
+			RegNum = val & 15;
+		}
+		public void RegWrite(byte val)
+		{
+			switch (RegNum)
+			{
+				case 0: pulse[0].WritePeriodLow(val); break;
+				case 1: pulse[0].WritePeriodHigh(val); break;
+				case 2: pulse[1].WritePeriodLow(val); break;
+				case 3: pulse[1].WritePeriodHigh(val); break;
+				case 4: pulse[2].WritePeriodLow(val); break;
+				case 5: pulse[2].WritePeriodHigh(val); break;
+				case 6: break; // noise period
+				case 7: // also noise disable
+					pulse[0].SetToneDisable(val.Bit(0));
+					pulse[1].SetToneDisable(val.Bit(1));
+					pulse[2].SetToneDisable(val.Bit(2));
+					break;
+				case 8: pulse[0].SetVolume(val); break; // also envelope enable
+				case 9: pulse[1].SetVolume(val); break; // also envelope enable
+				case 10: pulse[2].SetVolume(val); break; // also envelope enable
+				case 11: break; // envelope low
+				case 12: break; // envelope high
+				case 13: break; // envelope params
+				// ports 14 and 15 are not hooked up on Sunsoft 5B
+			}
+		}
+
+		public void SyncState(Serializer ser)
+		{
+			ser.BeginSection("Sunsoft5BAudio");
+			ser.Sync("RegNum", ref RegNum);
+			for (int i = 0; i < pulse.Length; i++)
+				pulse[i].SyncState(ser);
+			ser.EndSection();
+		}
+
+		Action<int> enqueuer;
+		void PulseAddDiff(int val)
+		{
+			enqueuer(val * 250);
+		}
+
+		public Sunsoft5BAudio(Action<int> enqueuer)
+		{
+			this.enqueuer = enqueuer;
+			for (int i = 0; i < pulse.Length; i++)
+				pulse[i] = new Pulse(PulseAddDiff);
+		}
+
+		public void Clock()
+		{
+			for (int i = 0; i < pulse.Length; i++)
+				pulse[i].Clock();
+		}
+	}
+}